Influence of ethanol on gastric secretion of acid, pepsin and mucin, and morphology of the gastric mucosal cells will be investigated in dogs. Functional and morphological correlationships of the gastric secretory cells will be studied also. The methods include determinations of acidity, pepsins, mucin of the gastric juice, ethanol in blood, radioimmunoassay of gastrin and secretin, dogs prepared with esophagostomy, gastric fistula and Heidenhain pouch or Pavlov pouch and light microscopic and electron microscopic examinations of gastric mucosal cells.